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标题：Very long chain n-3 and n-6 polyunsaturated fatty acids bind strongly to liver fatty acid-binding protein
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作者：Andrew W. Norris ; Arthur A. Spector
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2002
卷号：43
期号：4
页码：646-653
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Synthesis of n-3 and n-6 very long chain-PUFAs (VLC-PUFAs) from 18-carbon essential fatty acids is differentially regulated. The predominant product arising from n-3 fatty acids is docosahexaenoic acid (22:6n-3), with the liver serving as the main site of production. The synthetic pathway requires movement of a 24-carbon intermediate from the endoplasmic reticulum to peroxisomes for retroconversion to 22:6n-3. The mechanism of this intra-organelle flux is unknown, but could be binding-protein facilitated. We thus investigated binding of a series of previously untested VLC-PUFAs to liver fatty acid-binding protein (L-FABP). Three fluorometric assays were employed, all of which showed strong binding ( K_d ′ ~10⁻⁸ to 10⁻⁷ M) of 20-, 22-, and 24-carbon n-3 PUFAs to L-FABP. In contrast, synthesis of the predominant n-6 PUFA product, arachidonic acid, does not require intra-organelle transport. However, we found that n-6 VLC-PUFAs bound to L-FABP with affinities ( K_d ′ −10⁻⁸ to 10⁻⁷ M) comparable to their n-3 counterparts. Although these results raise the possibility that L-FABP may participate in the cytoplasmic processing of n-3 and n-6 VLC-PUFAs, there is no evidence on the basis of binding affinities that L-FABP accounts for differences in the predominant products formed by the n-3 and n-6 PUFA metabolic pathways. —Norris, A. W., and A. A. Spector. Very long chain n-3 and n-6 polyunsaturated fatty acids bind strongly to liver fatty acid-binding protein. J. Lipid Res. 2002. 43: 646–653.
关键词：24-carbon polyunsaturated fatty acids ; docosahexaenoic acid ; arachidonic acid ; fatty acid binding assay